All excellent points and right on! Thanks!
RR
From: Mike Puchol
[mailto:mike@starlink.sx]
Sent: Monday, February 21, 2022
11:42 PM
To: 'Daniel AJ Sokolov'; 'David
Lang'; dickroy@alum.mit.edu
Cc: starlink@lists.bufferbloat.net
Subject: RE: [Starlink] Starlink
Roaming
I did over-simplify so the point was better understood. On the optical
gateways, these exist already: https://mynaric.com/products/ground-capabilities/
Once you have an optical mesh in orbit, the only practical way to provide it
with massive capacity is optical links - there isn’t enough radio spectrum that
would do it (without a massive ground gateway network with enough physical
separation). You can create a network of optical gateways that guarantees a
number of them will not be impared by cloud cover at any given time. Optical
has the advantage of being license-free, too.
Best,
Mike
On Feb 22, 2022, 10:20 +0300, Dick Roy <dickroy@alum.mit.edu>,
wrote:
From: Starlink [mailto:starlink-bounces@lists.bufferbloat.net]
On Behalf Of Mike Puchol
Sent: Monday, February 21, 2022
9:35 PM
To: Daniel AJ Sokolov; David Lang
Cc: starlink@lists.bufferbloat.net
Subject: Re: [Starlink] Starlink
Roaming
Actually, laser
links would make gateway connectivity *worse*. If we take the scenario
attached, one gateway is suddenly having to serve traffic from all UTs that
were not previously under coverage.
A satellite under full load can saturate two gateway links by itself. If you
load, say, 20 satellites in an orbital plane, onto a single gateway, over ISL,
you effectively have 5% of each satellite’s capacity available (given an equal
distribution of demand, of course there will be satellites with no UTs to cover
etc.).
[RR] I think to do this analysis
correctly; one needs to consider the larger system and the time-varying loads
on the components thereof. What you say is true; just a bit over-simplified to
be maximally useful. Routing through complex congested networks is well-studied
problem and hnts at possible solutions can probably be found thereJ)
Eventually they will go for optical gateways, it’s the only way to get enough
capacity to the constellation, specially the 30k satellite version.
[RR] What do you mean by
“”optical gateway”? An optical link from the satellite to the ground station?
That would be real expensive at least power-wise and unreliable.
Best,
Mike
On Feb 22, 2022,
05:17 +0300, David Lang <david@lang.hm>, wrote:
On Mon, 21 Feb
2022, Daniel AJ Sokolov wrote:
On 2022-02-21 at
13:52, David Lang wrote:
They told me that I could try it, and it may work, may be degraded a
bit, or may not work at all. They do plan to add roaming capabilities in
the future (my guess is that the laser satellites will enable a lot more
flexibility)
Isn't that a very optimistic assessment? :-)
Laser links are great for remote locations with very few users, but how
could they relieve overbooking of Starlink in areas with too many users?
The laser links can reduce the required density of ground stations, but
they don't add capacity to the network. Any ground station not built
thanks to laser links adds load to other ground stations - and, maybe
more importantly, adds load to the satellite that does eventually
connect to a ground station.
Can laser links really help on a large scale, or are they just a small
help here and there?
My thinking is that the laser links will make it possible to route the traffic
from wherever I am to the appropriate ground station that I'm registered with
as
opposed to the current bent-pipe approach where, if I move to far from my
registered location, I need to talk to a different ground station.
Currently there are two limits in any area for coverage:
1. satellite bandwidth
2. ground station bandwidth
laser links will significantly reduce the effect of the second one.
We know that they can do mobile dishes (they are testing it currently on Elon's
gulfstream, FAR more mobile that I will ever be :-) )
David Lang
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